H.264 standard describes the various syntax elements that may occur in a bitstream. It specifies exactly how each syntax element should be processed and decoded in order to produce an output video sequence. It is important to know whether a particular decoder can handle a particular coded sequence. This is [...]
Three types of macroblocks are I Macroblock - An I Macroblock (I MB) is predicted using intra prediction from neighboring samples in the current frame. P Macroblock - A P Macroblock (P MB) is predicted from samples in a previously-coded frame which may be before or after the current picture [...]
Bitrate is a measurement of the amount of data used to encode a single second of video. It mainly affects the size and quality of your video. Bitrate is measured in bits per second (bps). While kilobits per second is used for measuring audio files, the same value isn’t used [...]
Slice layer Slice types Each coded picture, a coded frame or field, is composed of one or more slices, each containing a slice header followed an integral number of macroblocks. The number of macroblocksin a slice need not be constant. Possible scenarios for choosing slice sizes include: One slice per [...]
NAL Units Coded H.264 data is stored or transmitted as a series of packets known as Network Abstraction Layer Units, NAL Units or NALUs. Each NAL Unit consists of a 1-byte NALU header followed by a byte stream containing control information or coded video data. The header indicates the NALU [...]
A video sequence may be coded in Frame mode only, with no special coding of fields or interlaced video, or in Frame/Field mode, using special coding tools for interlaced video. If frame/field coding is enabled, each frame of video, a pair of fields, may be coded as a complete frame, [...]
MPEG-2 compression is the standard method for lossy video compression, developed by The Moving Pictures Expert Group (MPEG). The MPEG-2 compression method groups a number of video frames together, in what’s called a GOP (Group of Pictures). The length of a GOP is not specified by the MPEG standard, and [...]
Below figure shows hierarchical organization of the H.264/AVC syntax. The Network Abstraction Layer (NAL) consists of a series of NAL Units. Sequence Parameter Sets (SPS) and Picture Parameter Sets (PPS) are NAL units that signal certain common control parameters to the decoder. Coded video data is communicated in Video Coding [...]
Video compression is the process of converting digital video into a format that takes up less capacity when it is stored or transmitted. H.264 is a method and format for video compression. An encoder converts video into a compressed format and a decoder converts compressed video back into an uncompressed [...]
Goal of the prediction model in video coding is to reduce redundancy by forming a prediction of the data and subtracting this prediction from the current data. The prediction may be formed from Previously coded frames (a temporal prediction) Previously coded image samples in the same frame (a spatial prediction). [...]